Many, many years ago, before I went to culinary school, I tried my first molten chocolate cake. I was perplexed as to how they were able to have a perfectly firm cake on the outside while having a molten chocolate core inside. I was sure it was done by placing some sort of frozen chocolate center into he cake before baking, or by injecting the cake with a hot center after it had come out of the oven. Now I know better. Molten...